发明名称 |
Method and apparatus for slowing back spin of a rod string of a progressing cavity pump powered by an electric motor when power is lost |
摘要 |
A method and apparatus for slowing back spin of a rod string of a progressing cavity pump powered by an electric motor when power is lost. Pulse direct current voltage into the windings of the electric motor powering the progressing cavity pump to magnetize a stator of the electric motor thereby reducing the rotational speed of a rotor of the electric motor and consequently the rotational speed of the back spinning rod string of the progressing cavity pump.
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申请公布号 |
US5825143(A) |
申请公布日期 |
1998.10.20 |
申请号 |
US19960736341 |
申请日期 |
1996.10.23 |
申请人 |
LORD ELECTRICAL INDUSTRIAL DISTRIBUTORS LTD |
发明人 |
MONTGOMERY, RANDY |
分类号 |
E21B43/16;F04B47/02;F04B49/02;F04B49/06;H02P3/00;(IPC1-7):H02P3/00 |
主分类号 |
E21B43/16 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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